[New Blog Templates] Blog Templates don't display images if error on signup form

When a customer tries to sign up for a Pro Site, sometimes there are form errors. When the error happens and the form is displayed again for correct info, the New Blog Template screenshots that represent the templates disappear and the screenshot from theme is displayed. What can be done to correct this so that the screenshot I set in New Blog Templates continues to be shown correctly? Please see the client's video for an example.

https://www.youtube.com/watch?v=NtqVR9rK2AQ&feature=youtu.be